We want healthy bees Bee Diseases

Healthy Bees – How do we tell? Observations Look at landing board – do bees look normal? In & out activity Dead bees on landing board/in front of hive Sound After lifting inner cover Poop on hive? (lots? yellow or brown?) Mites? Wings? How does the brood look? Bee Temperament

Diseases affecting Brood

Healthy Bees & Brood

Healthy Brood Brood grouped together Uniform color (orangish) Capped brood is concave (center higher than edges) Holes – generally centered with smooth edges

American Foulbrood Cause: Paenibacillus (=Bacillus) larvae, a spore-forming bacterium Only affects larva, not adult bees Symptoms: Larva dies & darkens, brood cell cap shrinks into comb, foul smell, dead larva pulls out as dark, thready material

Dead larva develops a “false” tongue that points upward. American Foulbrood Dead larva develops a “false” tongue that points upward.

American Foulbrood

American Foulbrood Transmission: Foulbrood goo dries and forms spores Spores lodged in honey, dead larvae Nurse bees accidentally feed spores to the larvae Dried spores can last for 70+ years and are impervious to everything but high heat

No Treatment, Only Prevention American Foulbrood No Treatment, Only Prevention If you find it, get rid of diseased combs – burn or put in plastic bags and take to landfill Do not combine combs from diseased hive with healthy hive If found, contact state agency that oversees beekeepers Discard brood comb frames regularly (every 3 years)

American Foulbrood Prophylactic Issues WASBA: Treat hives in infected area with Terramycin (antibiotic) in sugar syrup, powdered sugar dust or shortening patty – stop treatment 2 weeks before nectar flow. Problem: Over 25% of AFB is Terramycin resistant

European Foulbrood Cause: Melissococcus plutonius, a bacterium Symptoms: Brown larva (dead) in uncapped cells; sour smell; larva twisted in bottom of cell Generally, no ropy goo (although atypical EFB has short ropy thread)

European Foulbrood Transmission: House bees cleaning out dead larva spread the disease

European Foulbrood Prevention Get Italian bees  (cleanliness) Healthy, well fed hives Dry, well ventilated hives in sunny site Requeen Treat hives with Terramycin (like American Foulbrood) in the spring – same issues re: antibiotic overtreatment

Chalkbrood Cause: Ascosphaera apis, a fungus Symptoms: Usually affects brood on edges of comb; larva turns white, then black

Chalkbrood

Chalkbrood

Chalkbrood Prevention – hive cleanliness Usual disappears on its own – during summer heat Requeen (breeding for cleanliness) Replace heavily infected combs Clear hive entrance of larval mummies Replace brood frames every 3 years

Sacbrood Cause: Virus morator aetatulas (microscopic) Symptoms: larva die in the brood cell, often upright, head black, when removed, look like they are in a sack

Sacbrood Treatment Often retreats on its own, no treatment necessary Requeen if disease persists Bees normally clean diseased area

Chilled brood Cause: Brood on outside of hive dies due to neglect (comb too cold) Don’t open the hive when temperature is below 50°F Treatment: Leave brood in same position in hive, do not move to outside

Disease comparison

Diseases affecting Adult Bees

Nosema 2 types - Cause: Fungus– Nosema apis & Nosema ceranae. Attacks the mid-gut area & causing the bees to get sick. Weakens them, weakens the hive.

Nosema

Nosema

Nosema Symptoms: Usually occurs in early spring. Will see lots of fecal material around hive Can only tell its nosema w/dead bee & microscope – visible spores. See www.scientificbeekeeping.com for method Bee guts look different – nosema gut swollen & white; healthy gut amber colored

Nosema (spores under microscope)

Nosema

Nosema Treatment: Non-traditional Essential oils added to sugar syrup: Feed 1 gallon sugar syrup with the following quantities of essential oils: 1/2 teaspoon of thyme, 1 teaspoon of Lemongrass, 1 teaspoon of Peppermint and 1 teaspoon of Sweet Orange.

Nosema Treatment: Traditional Feed the infected colonies ~1 gallon sugar syrup containing Fumigil-B in March/April (before nectar flow) Fall feeding may reduce Nosema in wintering bees Some beekeepers do preventative treatments w/Fumigillan in fall & spring

Paralysis Cause: Viral – 2 types (Chronic/Acute) Symptoms: bees tremble & appear to be paralyzed. If picked up by wings & dropped, fall to ground. Bees look old, shiny & greasy Treatment: Requeen to breed in resistance

Dysentery Condition/symptom, not a disease – essentially bee diarrhea Cause – winter food high in solids, causing water in the gut. Bees have to defecate in the hive (which they don’t normally do) Fecal matter inside the bee > 30-40% of body weight. Bees just can’t hold it.

Poisoning Bees killed by insecticide sprayed on trees & plants Can be carried back to the hive and affect other bees & brood Adults may have enlarged abdomens & show signs of paralysis Brood may die, remain white but flatten, or become yellowish grey or brown

Poisoning Illegal to use pesticides in a way not prescribed in directions – i.e., when fruit trees in bloom Ask neighbors not to spray for insects while fruit trees are in bloom New EPA labeling for neonicotinoids (voluntary)

Colony Collapse Disorder Bees simply disappear from hive, leaving queen, brood and very few bees Historically, bee disappearances in 1880s, 1920s, and 1960s 5 million colonies in 1940s to 2.5 million today Between 2006-2011, CCD caused losses of ~11% of all hive losses

Colony Collapse Disorder What causes CCD? No one really knows. It could be – Cyclical bee die offs Pests? Varroa mite contributes? (High levels of varroa mites found in collapsed hives)  Management issues? Too many bees, too close together? (commercial beekeepers) Environmental stressors? Pesticides – Neonicotinoids? Correlation, not causation The perfect storm?

Sources USDA Ag Research Service – www.ars.usda.gov www.beesource.com http://wasba.org/ www.cyberbee.net (photos)

Sources Vivian, John, Keeping Bees www.scientificbeekeeping.com Penn state: A field guide to Honey bees and their maladies, http://pubs.cas.psu.edu/FreePubs/PDFs/AGRS116.pdf

http://pubs.cas.psu.edu/FreePubs/PDFs/AGRS116.pdf